Could radiological parameters help to predict the failure of ureteral access sheath placement.

To identify the radiological parameters which may help to predict the success of ureteral access sheath (UAS) placement during retrograde intrarenal surgery (RIRS).The study included 49 patients in whom failure ureteral access sheath placement in RIRS and 49 control group patients who were successfully placement between January 2023 and December 2023. The age, gender, body mass index (BMI), non-contrast computed tomography (NCCT), and kidney ureter bladder (KUB) radiographs were compared between the two groups. Measurements of the anteroposterior (ap) diameter of the pelvic inlet, anteroposterior diameter of the pelvic outlet, interspinous distance diameter were taken from non-contrast computed tomography (NCCT), while pelvic anteroposterior diameter and pelvic lateral diameter were measured from kidney ureter bladder (KUB) radiography. There were no significant differences between the groups in age, gender, body mass index, ap pelvic inlet diameter, ap pelvic outlet, and interspinous distance diameter. However, a statistically significant difference was found between the pelvic ap diameter and pelvic lateral diameter values measured on the KUB radiography. The values for pelvic ap diameter and pelvic lateral diameter measured in the KUB radiographs can be used to predict the likelihood of UAS passage during RIRC procedures. However, further studies with larger patient groups are needed to establish a cut-off value.

Temporary Ureter Occlusion with Simultaneous Urinary Diversion via a Single-Access Route Using a 4-French Balloon Catheter and a Pigtail Nephrostomy Drainage Catheter.

Background and Objectives: This study evaluated the efficacy and safety of temporary ureteral occlusion combined with urinary diversion using a single-access route created by inserting a balloon catheter through a pigtail nephrostomy drainage catheter. With this approach, we aimed to offer an alternative for patients with ureteral leaks who are suboptimal surgical candidates. Materials and Methods: This retrospective study included nine patients (eight of which were bilateral cases and one was unilateral, totaling seventeen cases) who underwent the surgery between September 2023 and March 2024. The method involved gaining percutaneous access to the pelvicalyceal system, inserting a 4-French Fogarty balloon catheter through a pigtail nephrostomy catheter, and inflating the balloon at the proximal or mid-ureter. Results: All 17 cases achieved technical successful with no major complications. The procedure effectively relieved symptoms associated with urinary leakage in most patients. However, the significant deflation of the balloon catheter occurred in five cases (29.4%), with three (17.6%) experiencing complete deflation. In these five cases, the final balloon size was 5.81 mm (range: 0-8.9 mm), confirming a 25.0% decrease in size from pre- to post-procedure. Ureteral occlusion was 28.3 d long on average (range: 8-57 d). All patients experienced symptom relief during temporary ureteral occlusion. Except for two patients lost to follow-up, three patients showed symptom improvement with only PCN and four patients underwent surgical closure of the fistula tract before or after balloon catheter removal. Conclusions: This study confirms that this approach is safe and effective.

Robotic distal ureterectomy for high-risk distal ureteral urothelial carcinoma: a retrospective multicenter comparative analysis (ROBUUST 2.0 collaborative group).

BACKGROUND: The role of kidney-sparing surgery in patients with high-risk upper urinary tract urothelial carcinoma is controversial. The present study aimed to assess oncological and functional outcomes of robot-assisted distal ureterectomy in patients with high-risk distal ureteral tumors. METHODS: The ROBUUST 2.0 multicenter international (2015-2022) dataset was used for this retrospective cohort analysis. High-risk patients with distal ureteral tumors were divided based on type of surgery: robot-assisted distal ureterectomy or robot-assisted nephroureterectomy. A survival analysis was performed for local recurrence-free survival, distant metastasis-free survival, and overall survival. After adjusting for clinical features of the high-risk prognostic group, Cox proportional hazard model was plotted to evaluate significant predictors of time-to-event outcomes. RESULTS: Overall, 477 patients were retrieved, of which 58 received robot-assisted distal ureterectomy and 419 robot-assisted nephroureterectomy, respectively, with a mean (±SD) follow-up of 29.6 months (±2.6). The two groups were comparable in terms of baseline features. At survival analysis, no significant difference was observed in terms of recurrence-free survival (P=0.6), metastasis-free survival (P=0.5) and overall survival (P=0.7) between robot-assisted distal ureterectomy and robot-assisted nephroureterectomy. At Cox regression analysis, type of surgery was never a significant predictor of worse oncological outcomes. At last follow-up patients undergoing robot-assisted distal ureterectomy had significantly better postoperative renal function. CONCLUSIONS: Comparable outcomes in terms of recurrence-free survival, metastasis-free survival, and overall survival between robot-assisted distal ureterectomy and robot-assisted nephroureterectomy patients, and better postoperative renal function preservation in the former group were observed. Kidney-sparing surgery should be considered as a potential option for selected patients with high-risk distal ureteral UTUC.

Violation of onco-surgical principles is associated with survival outcomes in upper tract urothelial carcinomas after radical nephroureterectomy.

OBJECTIVE: Disease recurrence, particularly intravesical recurrence (IVR) after radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC), is common. We investigated whether violations of onco-surgical principles before or during RNU, collectively referred to as surgical violation (SV), were associated with survival outcomes.  Material and methods: Data from a consecutive series of patients who underwent RNU for UTUC 2001-2012 at Skåne University Hospital Lund/Malmö were collected. Preoperative insertion of a nephrostomy tube, opening the urinary tract during surgery or refraining from excising the distal ureter were considered as SVs. Survival outcomes in patients with and without SV (IVR-free [IVRFS], disease-specific [DSS] and overall survival [OS]) were assessed using multivariate Cox regression analyses (adjusted for tumour stage group, prior or concomitant bladder cancer, comorbidity and preoperative urinary cytology). RESULTS: Of 150 patients, 47 (31%) were subjected to at least one SV. Overall, SV was not associated with IVRFS (HR 0.81, 95% CI 0.4-1.6) but with worse DSS (HR 1.9, 95% CI 1.03-3.7) and OS (HR 1.9, 95% CI 1.2-3) in multivariable analysis. Additional analyses with a broader definition of SV including also preoperative instrumentation of the upper urinary tract (ureteroscopy and/or double J stenting) showed similar outcomes for DSS (HR 2.1, 95% CI 1.1-4.3). CONCLUSION: Worse survival outcomes, despite no difference in IVR, for patients that were subjected to the violation of sound onco-surgical principles before or during RNU for UTUC strengthen the notion that adhering to such principles is a cornerstone in upper tract urothelial cancer surgery.

Minimally invasive versus open ileal ureter with ileocystoplasty: comparative outcomes and 5-year experience.

PURPOSE: To present the experience of ileal ureter with ileocystoplasty (IUC), and compare the outcomes of IUC in minimally invasive procedures to open procedures. PATIENTS AND METHODS: From December 2017 to April 2023, twenty patients underwent IUC in open or minimally invasive (including laparoscopic and robotic) procedures. The baseline characteristics, perioperative data and follow-up outcomes were collected. Success was defined as relief of clinical symptoms, stable postoperative serum creatine and absence of radiographic obstruction. The perioperative and follow-up outcomes of open procedures and minimally invasive procedures were compared. RESULTS: The etiology included pelvic irradiation (14/20), urinary tuberculosis (3/20) and surgical injury (3/20). Bilateral ureter strictures were repaired in 15 cases. The surgeries conducted consisted of open procedures in 9 patients and minimally invasive procedures in 11 patients. Compared to open procedures, minimally invasive surgeries had less median estimated blood loss (EBL) (100 ml vs. 300 min, p = 0.010) and shorter postoperative hospitalization (27 d vs. 13 d, p = 0.004). Two patients in the open group experienced grade 3 complications (sigmoid fistula and acute cholecystitis in one patient, and pulmonary embolism in another patient). Over a median follow-up period of 20.1 months, the median bladder functional capacity was 300 ml, with a 100% success rate of IUC. CONCLUSION: IUC is feasible in both open and minimally invasive procedures, with acceptable complications and a high success rate. Minimally invasive procedures can have less EBL and shorter postoperative hospitalization than open procedure. However, prospective studies with larger groups and longer follow-up are needed.

A delayed diagnosis of iatrogenic ureteral injury results in increased morbidity.

This study aimed to register and analyse outcomes after iatrogenic ureteral injuries (IUI) with special emphasis on potential consequences of a delayed diagnosis, and further to analyse if the incidence of IUI has changed during the study period. 108 patients treated for an IUI during 2001-2021 were included. Injuries due to endourological procedures, planned tumour resection and traumatic injuries were excluded. All relevant information to answer the research questions were entered into a database. Chi-square and t-tests were used for categorical and continuous variables respectively. Regression analysis was used to evaluate potential change of incidence in IUIs over time. Our results showed that most IUIs (74, 69%) were caused by gynaecological surgery. 49 (45%) had a delayed diagnosis (not diagnosed intraoperatively). Younger age (mean 50 vs 62 years, p < 0.001) and benign indication for laparoscopic hysterectomy (OR 8.0, p < 0.001) predisposed for a delayed diagnosis. Patients with a delayed diagnosis had a higher number of secondary injury related procedures (mean 4.6 vs 1.7, p < 0.001), hospital admissions (mean 3.0 vs 0.8, p < 0.001) and longer hospital stays (mean 20.6 vs 3.9 days p < 0.001) compared to patients with an intraoperative diagnosis. There was complete recovery for 91% of the patients. We did not observe any changes in IUI incidence during the study period. In conclusion, our study underlines that IUI can cause major morbidity for the patient affected if not diagnosed intraoperatively. Benign indication and younger age are predictors for a delayed diagnosis. The prognosis is good, with 91% full recovery. No significant changes in incidence of IUIs were observed.

Is Stent-Free Ureteroenteric Anastomosis Associated With Lower Ureteroenteric Strictures After Robot-Assisted Radical Cystectomy and Ileal Conduit?

INTRODUCTION: We aimed to investigate the differences in perioperative outcomes, especially ureteroenteric strictures, between patients who underwent a stented ureteroenteric anastomosis at the time of robot-assisted radical cystectomy (RARC) and ileal conduit vs those who did not. METHODS: A retrospective review of our RARC database was performed (2009-2023). Patients were divided into those who received stented ureteroenteric anastomosis vs those who did not. Propensity score matching was performed in the ratio of 3 (stented ureteroenteric anastomosis) to 1 (stent-free) in terms of age, gender, BMI, race, American Society of Anesthesiologists score, neoadjuvant chemotherapy, Charlson Comorbidity Index, prior radiation therapy, previous abdominal surgery history, clinical T3/clinical T4 stage, preoperative metastasis, and preoperative hydronephrosis. A cumulative incidence curve was used to depict ureteroenteric strictures and a Cox regression model was used to identify variables associated with ureteroenteric strictures. RESULTS: Four hundred eighty-eight patients underwent RARC, 366 individuals underwent a stented ureteroenteric anastomosis, and 122 patients underwent a stent-free approach. There was no significant difference in 90-day overall complications, high-grade complications, readmissions, UTIs, leakage, and ileus (P > .05). Ureteroenteric strictures occurred at a rate of 13% and 18% at 1 and 2 years, respectively in the stented group, vs 7% and 10% in the stent-free group (P = .05). Stent placement was significantly associated with ureteroenteric strictures. CONCLUSIONS: Stent-free ureteroenteric anastomosis was associated with fewer strictures following RARC and ileal conduit.

Robotic-assisted native pyeloureterostomy with indocyanine green, after kidney transplantation.

INTRODUCTION: Postoperative ureteral strictures and vesicoureteral reflux after ureteroneocystostomy for kidney transplant can be managed by endoscopic procedures like balloon dilation and endoscopic injections. Complicated/recurrent cases, however, are usually managed by reconstructive surgery. We hereby highlight our technique of robotic-assisted native pyeloureterostomy with indocyanine green (ICG). MATERIALS AND SURGICAL TECHNIQUE: A 57-year-old woman, diagnosed with grade 4 vesicoureteral reflux on her transplanted kidney, was considered a candidate for ureteral reimplantation. After an endoscopic part, where the ICG is inserted into the renal pelvis, we proceed with the robotic native pyeloureterostomy. The renal pelvis of the transplanted kidney was identified with the help of the ICG in firefly mode. After the dissection of the graft pelvis, we performed a tension-free pyeloureterostomy using the native ureter. The postoperative course was uneventful and the patient was discharged on the third postoperative day. DISCUSSION: Robotic-assisted pyelo-ureterostomy appears as a safe and efficient technique for management of complicated urological complications postrenal transplantation using the native ureter. Intrapelvic ICG injection, not possible with open surgery, helps identifying the grafted pelvis thus reducing operative time and avoiding unnecessary dissection of the vascular hilum of the graft. Because of minimal dissection and the short operative time, abdominal drainage is unnecessary and the postoperative course is usually uneventful with a fast discharge from the hospital.

A Forgotten Double-J Ureteric Stent as the Core of a Bladder Stone: A Case Report and Literature Review.

BACKGROUND Double-J (D-J) ureteric stents are widely applied in urological operations as they play a vital role in maintaining postoperative functionality of the patient's urinary system and thereby accelerating recovery. D-J stent encrustation may occur due to prolonged retention and lead to secondary complications. We report the case of a forgotten D-J stent that gradually formed into a bladder stone. CASE REPORT A 54-year-old man was referred to the Urology Department due to intermittent hematuria, left flank pain, and lower urinary tract symptoms that persisted for 2 weeks. His history was significant for undergoing left ureterolithotripsy followed by the implantation of an ipsilateral D-J stents 2 years ago in a local hospital. The patient did not follow-up regularly or actively seek medical attention for his urinary tract symptoms. Computed tomographic urography revealed a hyperdense tubular object protruding from the left distal ureter to the bladder. The patient underwent cystolithotripsy, left ureteric stent removal, and left ureteroscopy to clear away the bladder stone and its D-J stent core. CONCLUSIONS Formation of bladder stones secondary to prolonged indwelling D-J stent and its encrustation is not uncommon in developing countries where the level of public education is low. Prompt D-J stent removal can prevent complications associated with its retention and avoid unnecessary secondary procedures. Endoscopic urologic procedures are safe and feasible management options, and doctor-to-patient communication is vital for a better prognosis.

Comparison of the efficacy and complications of tolterodine and α-adrenergic receptor blockers in improving ureteral stent-related symptoms: A systematic review and meta-analysis.

OBJECTIVE: We conducted a systematic evaluation of the therapeutic efficacy and complications of tolterodine and α-adrenergic receptor blockers in alleviating ureteral stent-related symptoms. METHODS: Until August 2023, we conducted a comprehensive literature search on PubMed, Embase, Web of Science, and Cochrane Library to identify randomized controlled trials evaluating the efficacy and complications of tolterodine and α-adrenergic receptor blockers in treating ureteral stent-related symptoms. Two reviewers independently screened studies and extracted data. The scores from various domains of the Ureteral Stent Symptom Questionnaire (USSQ) were summarized and compared, and statistical analysis was performed using RevMan 5.4.0 software. RESULTS: A total of 8 studies met the inclusion criteria for our analysis. These studies were conducted at different centers. All studies were randomized controlled trials, involving a total of 487 patients, with 244 patients receiving α-adrenergic receptor blockers and 243 patients receiving tolterodine. The results showed that tolterodine demonstrated significantly better improvement in body pain (MD, 1.56; 95% CI [0.46, 2.66]; p = 0.005) (MD, 0.46; 95% CI [0.12, 0.80]; p = 0.008) (MD, 3.21; 95% CI [1.89, 4.52]; p = 0.00001) among patients after ureteral stent placement compared to α-adrenergic receptor blockers at different time points. Additionally, at 4 weeks, tolterodine showed superior improvement in general health (MD, 0.15; 95% CI [0.03, 0.27]; p = 0.01) and urinary symptoms (MD, 1.62; 95% CI [0.59, 2.66]; p = 0.002) compared to α-adrenergic receptor blockers, while at 6 weeks, tolterodine showed better improvement in work performance (MD, -1.60; 95% CI [-2.73, -0.48]; p = 0.005) compared to α-adrenergic receptor blockers. Additionally, the incidence of dry mouth (RR, 4.21; 95% CI [1.38, 12.87]; p = 0.01) is higher with the use of tolterodine compared to α-adrenergic receptor blockers. However, there were no significant statistical differences between the two drugs in other outcomes. CONCLUSION: This meta-analysis suggests that tolterodine is superior to α-adrenergic receptor blockers in improving physical pain symptoms after ureteral stent placement, while α-adrenergic receptor blockers are more effective than tolterodine in enhancing work performance. Additionally, the incidence of dry mouth is higher with the use of tolterodine compared to α-adrenergic receptor blockers. However, higher-quality randomized controlled trials are needed to further investigate this issue.

Distinguishing the Uterine Artery, the Ureter, and Nerves in Laparoscopic Surgical Images Using Ensembles of Binary Semantic Segmentation Networks.

Performing a minimally invasive surgery comes with a significant advantage regarding rehabilitating the patient after the operation. But it also causes difficulties, mainly for the surgeon or expert who performs the surgical intervention, since only visual information is available and they cannot use their tactile senses during keyhole surgeries. This is the case with laparoscopic hysterectomy since some organs are also difficult to distinguish based on visual information, making laparoscope-based hysterectomy challenging. In this paper, we propose a solution based on semantic segmentation, which can create pixel-accurate predictions of surgical images and differentiate the uterine arteries, ureters, and nerves. We trained three binary semantic segmentation models based on the U-Net architecture with the EfficientNet-b3 encoder; then, we developed two ensemble techniques that enhanced the segmentation performance. Our pixel-wise ensemble examines the segmentation map of the binary networks on the lowest level of pixels. The other algorithm developed is a region-based ensemble technique that takes this examination to a higher level and makes the ensemble based on every connected component detected by the binary segmentation networks. We also introduced and trained a classic multi-class semantic segmentation model as a reference and compared it to the ensemble-based approaches. We used 586 manually annotated images from 38 surgical videos for this research and published this dataset.

Exploring the feasibility of indocyanine green fluorescence for intraoperative ureteral visualisation in robotic transvaginal natural orifice transluminal endoscopy surgery during endometriosis resection.

BACKGROUND: To assess the feasibility of use of indocyanine green (ICG) in identifying and minimising urinary tract injury during surgical resection of endometriosis through robotic transvaginal natural orifice transluminal endoscopy surgery (RvNOTES). METHODS: We conducted a retrospective case series in two academic tertiary care hospitals. We examined 53 patients who underwent RvNOTES hysterectomy with planned endometriosis resection. RESULTS: The study involved 53 patients undergoing RvNOTES with ICG fluorescence for endometriosis resection. Mean patient age was 37.98 ± 6.65 years. Operative time averaged 181.32 ± 53.94 min, with estimated blood loss at 45.57 ± 33.62 mL. Postoperative stay averaged 0.23 ± 0.47 days. No ICG-related complications occurred. CONCLUSION: No complications occurred with ICG fluorescence in RvNOTES. It appears to be a safe option for ureteral localisation and preservation. ICG fluorescence is widely used in diverse medical specialities for identifying ureters during complex surgeries. Larger studies are needed to firmly establish its advantages in intraoperative ureteral visualisation during RvNOTES for deep infiltrative endometriosis.

Disposable grasper-integrated flexible cystoscope for ureteral stent removal in transplanted patients; focus on feasibility, safety, and patient experience. Results and micro-cost analysis from a tertiary referral center.

INTRODUCTION & OBJECTIVES: To evaluate ureteral stent removal (SR) using a grasper-integrated disposable flexible cystoscope (giFC-Isiris ®, Coloplast ®) after kidney transplantation (KT), with a focus on feasibility, safety, patient experience, and costs. MATERIAL AND METHODS: All consecutive KT undergoing SR through giFC were prospectively enrolled from January 2020 to June 2023. Patient characteristics, KT and SR details, urine culture results, antimicrobial prescriptions, and the incidence of urinary tract infections (UTI) within 1 month were recorded. A micro-cost analysis was conducted, making a comparison with the costs of SR with a reusable FC and grasper. RESULTS: A total of 136 KT patients were enrolled, including both single and double KT, with 148 stents removed in total. The median indwelling time was 34 days [26, 47]. SR was successfully performed in all cases. The median preparation and procedure times were 4 min [3,5]. and 45 s[30, 60], respectively. The median Visual Analog Scale (VAS) score was 3 [1, 5], and 98.2% of patients expressed willingness to undergo the procedure again. Only one episode of UTI involving the graft (0.7%) was recorded. Overall, the estimated cost per SR procedure with Isiris ® and the reusable FC was 289.2€ and 151,4€, respectively. CONCLUSIONS: This prospective series evaluated the use of Isiris ® for SR in a cohort of KT patients, demonstrating feasibility and high tolerance. The UTI incidence was 0.7% within 1 month. Based on the micro-cost analysis, estimated cost per procedure favored the reusable FC.

Single-port-plus-one robot-assisted laparoscopic Lich-Gregoir direct nipple ureteral extravesical reimplantation in pediatric primary obstructive megaureter, comparing to laparoscopic cohen.

PURPOSE: To compare the effects of a single-port-plus-one robotic laparoscopic-modified Lich-Gregoir direct nipple approach and traditional laparoscopic Cohen in treating pediatric primary obstructive megaureter. MATERIALS AND METHODS: The clinical data of 24 children with primary obstructive megaureter from January 2021 to November 2021 were analyzed retrospectively. Among them, 12 children (8 boys and 4 girls, the average age were 17.17 ± 6.31 months) treated with the laparoscopic Cohen method were defined as group C. The remaining 12 children (7 boys and 5 girls, the average age was 17.33 ± 6.99 months) underwent single-port-plus-one robotic laparoscopic-modified Lich-Gregoir direct nipple ureteral extravesical reimplantation were defined as group L. The parameters of pre-operation, intraoperative and postoperative were compared. RESULTS: There were no differences in the patient characteristics and average follow-up time between the two groups (P > 0.05).The obstruction resolution rate was 100% in both groups. The total operation time in group L is slightly longer than that in group C(P < 0.001),but the intraperitoneal operation time of the two groups was comparable(P > 0.05). The postoperative parameters included blood loss, gross haematuria time, indwelling catheterization time and hospitalization time in group L is shorter than group C(P < 0.05). One year post-operation, decreasing in ureteral diameter and APRPD, and increasing in DRF were remarkably observed in both two groups(P < 0.05). Ureteral diameter, APRPD, and DRF were not significantly different both in pre-operation and post-operation between Group L and Group C(P > 0.05). CONCLUSION: Single-port-plus-one robot-assisted laparoscopic-modified Lich-Gregoir direct nipple approach and traditional laparoscopic Cohen are both dependable techniques for ureteral reimplantation in the treatment of pediatric primary obstructive megaureter. Since Lich-Gregoir can preserve the physiological direction of the ureter and direct nipple reimplantation enhances the effect of anti-refluxing, this technique is favorable for being promoted and applied in robot surgery.

Flexible Ureteroscopic Guided Laparoscopic Ureteroplasty For The Treatment Of Ureteral Stricture.

INTRODUCTION: Ureteral stricture is often a consequence of urolithiasis or previous endourological procedures (1-3). Precisely delineating the stricture zone intraoperatively is crucial to minimize ureter shortening and target only the affected tissue (4, 5). Flexible ureteroscopy offers a significant advantage in this regard. OBJECTIVE: This video aims to demonstrate the step-by-step technique of flexible ureteroscopic guided laparoscopic ureteroplasty for treating ureteral stricture caused by urolithiasis and prior endourological interventions. PATIENT AND METHODS: We present a case of a 36-year-old male with a history of urolithiasis and unsuccessful endourological treatments, including endoureterotomy and balloon dilation, diagnosed with re-stenosis of the proximal ureter of 1 cm through ureteroscopy and pyelography. He underwent a successful laparoscopic ureteroplasty. While the lead surgeon performed the laparoscopy, an assistant conducted the flexible ureteroscopy. Intraoperatively, using transillumination facilitated by the flexible ureteroscope, we can precisely identify the narrowed area, allowing for resection of only the damaged segment. Subsequently, we perform the end-to-end ureteroplasty, confirming its patency through the seamless passage of the ureteroscope. Upon completion, we employ a fat patch to safeguard the anastomosis. RESULTS: The patient was discharged on the third postoperative day. Double J stent was removed six weeks after surgery. Symptoms resolved. Renal function improved: eGFR 49 to 67 ml/min. Furthermore, improvement was observed in the DTPA scan, and a decrease in hydronephrosis was noted on the follow-up tomography. CONCLUSION: Flexible ureteroscopy effectively identifies the stricture zone in laparoscopic ureteroplasty, enhancing surgical precision and outcomes. This approach is safe, effective, and reproducible, offering a valuable technique in the surgical treatment of ureteral strictures.

[Prognosis of ureteral dilatation during procedures using a ureteral access sheath in patients with urolithiasis].

AIM: To improve the results of treatment of patients with urolithiasis who underwent endoscopic interventions using a ureteral access sheath (UAS) by developing a predictive model of ureteral dilatation without pre-stenting. MATERIALS AND METHODS: A total of 180 patients with kidney stones up to 20 mm were included in the study. They were divided into two groups: in the group 1 (n=79) UAS of 12/14 Ch was used, while in group II (n=101) UAS of 10/12 Ch was inserted. In group I, 48 (60.8%) patients underwent micropercutaneous nephrolithotomy and in 31 (39.2%) retrograde intrarenal surgery was done, compared to 42 (41.6%) and 59 (58, 4%) of patients in group 2. A non-inclusion criterion was a history of ureteral stenting. At the stage of preoperative diagnosis, 60 minutes before the X-ray examination, the patient took a single dose of 80 mg of furosemide per os to improve visualization of the upper urinary tract. After digital processing of computed tomography data and 3D-reconstruction of the upper urinary tract using the DICOM image processing program "RadiAnt DICOM Viewer," a visual assessment of the ureter was carried out to exclude significant deviations and strictures. The ureteral width was measured at three points: pyeloureteral segment, the level of the iliac bifurcation and intramural part. The number of cases of successful insertion of UAS and the rate of damage to the ureteral wall according to the classification proposed by O. Traxer and A. Thomas (2012) were analyzed. The prediction of successful insertion of a UAS was carried out using ROC analysis. RESULTS: In group 1, successful insertion of UAS was observed in 37 (46.8%) patients compared to 84 (83.2%) patients in group 2. In the remaining 42 (53.2%) and 17 (16.8%) cases, respectively, placement of UAS was not possible due to significant tissue resistance and high risk of traumatic injury. The average ureteral diameter at the points of physiological narrowing in patients with successful insertion of 12/14 Ch UAS were 2.0+/-0.1 mm, compared to 1.2+/-0.4 mm in those with failed insertion (p<0.05). In the group 2, similar indicators were 1.6+/-0.1 mm and 1.2+/-0.5 mm, respectively (p<0.05). According to ROC analysis, the diagnostic efficiency of the predictive model when using 12/14 Ch and 10/12 Ch UAS was confirmed by high AUC values (0.925 [95% CI 0.871-0.98] and 0.944 [95% CI 0.89=0.97], respectively). The total number of patients with ureteral injuries was 35 (44.3%) and 40 (39.6%) in groups with 12/14 Ch and 10/12 Ch UAS, respectively. At the same time, complications of the I degree were observed in 24 (30.4%) patients of the group 1 and in 31 (30.7%) patients of the group 2, while injuries of II degree were detected in 10 (12.7%) and 9 (8.9%) cases, respectively (p>0.05). Only in 1 (1.3%) patient, when 12/14 Ch UAS was inserted, grade III damage to the ureteral wall was determined. CONCLUSION: The proposed technique for measuring the cross-section of the ureter allows to predict the successful insertion of UAS at the preoperative stage. The probability of successful passage of UAS of 10/12 and 12/14 Ch in patients with ureteral diameter in physiological narrowings of more than 1.6 mm and 2 mm, respectively, is 95%. An insertion of UAS is a safe procedure, and most complications are classified as grades I or II.

Evaluation of renovated double J stents using ureter models with and without stenosis.

PURPOSE: Commercial double J stents (DJS) have a uniform shape regardless of the specific nature of various ureteral diseases. We tested renovated DJS and compared them with conventional DJS using ureter models. METHODS: One straight ureter model included stenosis at the distal ureter near the ureterovesical junction and the other did not. We used conventional DJS and renovated 5- and 6-Fr soft DJS for ureter stones and 6-, 7-, and 8.5-Fr hard DJS for tumors. The DJS comprised holes in the upper, middle, or lower one-third of the shaft (length, 24 cm; 2-cm-diameter coils at both ends). More holes were created along the shaft based on the ureteral disease location. Conventional DJS had holes spaced 1 cm apart along the shaft. Renovated DJS had holes spaced 1 cm apart along the shaft with 0.5-cm intervals on the upper, middle, or lower one-third of the shaft. Urine flow was evaluated. RESULTS: As the DJS diameter increased, the flow rate decreased. The flow rates of DJS with holes in the lower shaft were relatively lower than those of conventional DJS and DJS with holes in the upper and middle shafts. In the ureter model without stenosis, 6-, 7-, and 8.5-Fr renovated stents exhibited significantly higher flow rates than conventional stents. In the ureter model with stenosis, 5-, 6-, 7-, and 8.5-Fr renovated stents did not exhibit significantly higher flow rates than conventional stents. CONCLUSION: Renovated stents and conventional stents did not exhibit significant differences in urine flow with stenosis.

Should a Refluxing Internal Diversion Be Considered a Temporizing Procedure? Extended Follow-up and Outcomes After Side-to-Side Ureterovesicostomy for Primary Obstructive Megaureter in Young Children.

PURPOSE: We describe long-term outcomes, including UTIs and need for reimplantation, after ureterovesicostomy (UV) as a lasting surgical procedure for children with primary obstructive megaureter (POM). MATERIALS AND METHODS: Children referred to our institution between 2016 and 2023 who underwent refluxing UV were analyzed. POM was defined as hydroureteronephrosis with distal ureteral dilatation > 7 mm and a negative workup for other etiologies of hydronephrosis. We assessed for surgical outcomes, complications, rate of UTI, and improvement in upper tract dilatation. Statistical analyses assessed for change in hydronephrosis metrics over follow-up. RESULTS: Among 183 patients diagnosed with POM, 47 (24%) underwent UV. Median age of presentation, surgery, and follow-up was 2, 9, and 43 months, respectively. A total of 7 patients developed 30-day complications: Clavien-Dindo grade 1 in 2 (transient urinary retention) and grade 2 in 5 (UTIs). During monitoring 14 (30%) developed UTIs and 7 (15%) required ureteral reimplant or UV takedown. After surgery there was a significant decrease in the proportion of patients with high-grade hydronephrosis, anteroposterior renal pelvis diameter, and maximum ureteral dilatation. CONCLUSIONS: Refluxing UV is a safe alternative to cutaneous diversion in POM. Most patients had improvement in upper tract dilatation with an acceptable short-term complication rate and need for reoperation (in comparison to routine later reimplantation). Our experience suggests that monitoring alone after UV is feasible, and that selective subsequent reconstruction is a reasonable strategy.